One-way clutch

ABSTRACT

A full type one-way clutch is provided which is superior in the responsiveness of the clutch without lowering the torque-transmitting capability. Rollers are received in a full type state in the space between an outer ring having inclined cam surfaces on the inner peripheral surface thereof and a rotary shaft. By engaging a spring for biasing the rollers in such a direction as to engage the cam surfaces in a groove formed in the inner peripheral surface of the outer ring instead of being disposed between the rollers, and keeping all the rollers in abutment with one another, it is possible to reliably and instantly transmit the biasing force of the spring to all the rollers without reducing the torque-transmitting ability and improve the responsiveness of the clutch.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a one-way clutch using rollers as engaging elements.

[0002] As one-way clutches in which rollers are engaging elements, ones disclosed in japanese patent publication 47-43645 are known. With these one-way clutches, as shown in FIGS. 16 and 17, between the inner peripheral surface of an outer hollow member (outer member) 61 and the outer peripheral surface of an inner shaft member (inner member) 62, rollers 63 are housed in a so-called full-type state so as to surround the inner shaft member 62 while abutting each other. Each roller 63 is adapted to engage one of a plurality of inclined cam surfaces 64 formed on the inner peripheral surface of the outer hollow member 61 in one direction due to the wedge effect. When the outer hollow member 61 rotates clockwise or the inner shaft member 62 rotates counterclockwise, each roller 63 engages its respective cam surface 64, so that torque is transmitted.

[0003] With the one-way clutch shown in FIG. 16, the rollers 63 are housed so as to surround the entire circumference of the inner shaft member 62. When the outer hollow member 61 or the inner shaft member 62 rotates in the above-said rotational direction, due to the frictional force between the rotary members and the rollers 63, the rollers are adapted to engage the cam surfaces 64. In this embodiment, when frictional force acts on one of the rollers 63, since the rollers engage with one another, all the rollers engage the cam surfaces 64.

[0004] With the one-way clutch shown in FIG. 17, one of the rollers 63 housed in a full-type state is replaced with a spring roller 65. By the resilience accompanying its resilient deformation, the spring roller 65 urges the adjacent roller 63, so that all the rollers abutting one another, engage the cam surfaces 64. Instead of the spring roller 65, a resilient roller such as a rubber roller or a resilient member such as a leaf spring may be used.

[0005] Such full type one-way clutches aim to increase the torque-transmitting capability by increasing the number of rollers arranged and to make a compact design possible by eliminating a cage for rollers.

[0006] These conventional full type one-way clutches have the following problems. With the one-way clutch shown in FIG. 16, because the production of frictional force is unstable, it is impossible to reliably bring the rollers into engagement with the cam surfaces, so that the clutch sometimes does not operate.

[0007] On the other hand, with a one-way clutch of the type shown in FIG. 17, since the resilient member disposed between the rollers housed in a full-type state such as a spring roller sometimes shrinks excessively due to resilient deformation, a space may be formed between any adjacent rollers or between the resilient member and the adjacent roller, thus making it impossible to instantly and reliably transmit the biasing force of the resilient member to all the rollers. This may cause a lowering of the torque-transmitting capability or a delay in turning on and off of the clutch.

[0008] An object of this invention is to provide a full type one-way clutch that is superior in the responsiveness without lowering the torque-transmitting capability.

SUMMARY OF THE INVENTION

[0009] According to this invention, there is provided a one-way clutch comprising an outer member having an inner peripheral surface, an inner member having an outer peripheral surface, one of the inner and outer peripheral surfaces being formed with a plurality of inclined cam surfaces and the other being formed into a cylindrical surface, rollers as engaging members arranged between the outer member and the inner member at such positions as to oppose the cam surfaces, and a resilient member for biasing the rollers in such a direction as to engage the cam surfaces, characterized in that the rollers are brought into abutment with one another directly or through auxiliary rollers having a smaller diameter than the rollers, and that the resilient member is brought into engagement with one of the inner peripheral surface of the outer member and the outer peripheral surface of the inner member to transmit the biasing force of the resilient member to all of the rollers through the rollers abutting one another.

[0010] By engaging the roller-biasing resilient member on the inner peripheral surface of the outer member or the outer peripheral surface of the inner member, all the rollers can always maintain a mutually abutting state directly or through the auxiliary rollers without any resilient members disposed between the rollers, so that it is possible to reliably and instantly transmit the biasing force of the resilient members to all the rollers.

[0011] By making at least one of the inner member and outer member of a sintered metal or by blanking a steel plate, it is possible to manufacture the outer member and inner member at a low cost.

[0012] If the blanking is fine-blanking to the finished dimension of the outer member or inner member, it is possible to eliminate finish working such as shaving and reduce the occurrence of thermal strain during heat treatment.

[0013] By disposing the auxiliary rollers at positions where the resilient members are provided, it is possible to increase the space for receiving the resilient members, and to increase the biasing force to the rollers by use of a larger resilient member.

[0014] As the resilient members, steel springs having tongue biasing the rollers may be used.

[0015] By integrally forming torque-transmitting means on the outer periphery of the outer member, it is possible to reduce the number of parts and simplify the mounting work of the clutch.

[0016] The torque-transmitting means may be ribs formed on the outer periphery of the outer member.

[0017] By replacing at least one of the rollers by an engaging element having the same outer diameter as the rollers but having a different shape therefrom, it is possible to improve the retaining ability of grease and oil on the cam surfaces and the cylindrical surface, and thus to reduce the idling torque of the one-way clutch.

[0018] As the engaging element having a different shape, a grooved roller formed with at least one annular groove on the cylindrical surface of the roller, or a short roller shorter in length than the rollers may be used.

[0019] By forming independent, minute recesses in the surface of the rollers in a random manner, it is possible to form a sufficient oil film on the surfaces of the rollers, reduce the idling torque and suppress wear due to sliding during idling.

[0020] If the surface of the rollers formed with said recesses has such an average surface roughness that when indicated in terms of minimum root mean square RMS, the ratio RMS (L)/RMS (C) of the axial average surface roughness RMS (L) of the rollers to the circumferential average surface roughness RMS (C) is not more than 1.0 and the SK value, which is a parameter of surface roughness, is not more than −1.6 both in the axial and circumferential directions of the rollers, oil film can be more easily formed for circumferential sliding of the rollers, so that it is possible to improve the suppressing effect of wear due to sliding during idling.

[0021] Such surfaces of the rollers can be formed by special barrel polishing. The SK value represents the degree of balance of the distribution of protrusions and recesses with reference to the reference surface. If they are distributed symmetrically with respect to the reference surface, the SK value will be zero. The greater the rate of recesses to protrusions, the greater the negative value. Thus, by setting the SK value at −1.6 or under, it is possible to provide oil-retaining recesses sufficiently.

[0022] By forming, in the inner peripheral surface of the outer member or the outer peripheral surface of the inner member formed with the cam surfaces, at least one groove extending in the axial direction, and engaging the resilient member in the groove, it is possible to facilitate the mounting of the resilient members.

[0023] By having one end of the resilient member tapered, it is possible to insert the resilient member from the tapered end and smoothly mount it without forcibly deflecting it.

[0024] By providing side plates for guiding both end faces of the rollers, and by providing a means for engaging the side plate to the end face of the outer member or inner member, it is possible to prevent the rollers from coming out and to simplify the assembling of the one-way clutch.

[0025] The means for engaging the side plate may be protrusions formed on the side plate at a plurality of points so as to engage in recesses formed in the end face of the outer member or inner member.

[0026] By forming the cam surfaces on the outer periphery of the inner member, bringing the resilient member into engagement with the outer periphery of the inner member, and forming a torque-transmitting means on the inner periphery of the inner member, it is possible to minimize the influence of centrifugal face by making the rollers stationary during idling if the outer member is a rotation-transmitting side as with e.g. a clutch for a stator in a torque converter and thus to stabilize the idling properties.

[0027] The torque-transmitting means formed on the inner periphery of the inner member may be a serration.

[0028] With the one-way clutch in which the cam surfaces are formed on the outer periphery of the inner member, by forming an annular groove in an inner cylindrical surface of the outer member, it is possible to increase the retaining ability of grease on the cylindrical surface and thus to reduce the idling torque.

[0029] With the one-way clutch in which the cam surfaces are formed on the outer periphery of the inner member, by mounting it in a stator of a torque converter, it is possible to assure excellent clutch properties and reduce the cost.

[0030] Other features and objects of the present invention will become apparent from the following description made with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]FIG. 1A is a front view of a one-way clutch of a first embodiment;

[0032]FIG. 1B is a sectional side view of the same;

[0033]FIG. 2A is a front view of a spring of the same;

[0034]FIG. 2B is a side view of the same;

[0035]FIG. 3 is a front view of a one-way clutch of a second embodiment;

[0036]FIG. 4A is a front view of a rubber of the same;

[0037]FIG. 4B is a side view of the same;

[0038]FIG. 5 is a front view of a one-way clutch of a third embodiment;

[0039]FIG. 6A is a front view of a coil spring of the same;

[0040]FIG. 6B is a side view of the same;

[0041]FIG. 7A is a sectional side view of a one-way clutch of a fourth embodiment;

[0042]FIG. 7B is a front view of the same with the side plate removed;

[0043]FIG. 8 is a front view of the side plate of the same;

[0044]FIG. 9A is a front view of a spring used in the fourth embodiment;

[0045]FIG. 9B is a side view of the same;

[0046]FIG. 10 is a front view of a one-way clutch of a fifth embodiment with the side plate removed;

[0047]FIG. 11A is a partial enlarged front view of the same;

[0048]FIG. 11B is a developed view of rollers of FIG. 11A;

[0049]FIGS. 12A and 12B are developed views showing modified examples of arrangements of rollers;

[0050]FIG. 13A is a front view of a one-way clutch of a sixth embodiment;

[0051]FIG. 13B is a sectional side view of the same;

[0052]FIG. 14 is a vertical sectional view of a torque converter in which the one-way clutch of FIG. 13 has been mounted;

[0053]FIG. 15A is a front view of a one-way clutch of a seventh embodiment;

[0054]FIG. 15B is a sectional side view of the same;

[0055]FIG. 16 is a partially omitted sectional view of a conventional one-way clutch; and

[0056]FIG. 17 is a partially omitted sectional view of another conventional one-way clutch.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0057] With reference to FIGS. 1-15, the embodiments of this invention will be described. FIGS. 1 and 2 show the first embodiment. This one-way clutch has, as shown in FIGS. 1A and 1B, a plurality of inclined cam surfaces 2 formed on the inner peripheral surface of an outer ring 1 as an outer member made of a sintered metal. Rollers 4 are housed between these cam surfaces 2 and an outer cylindrical surface of a rotary shaft 3 as an inner member in a full-type state.

[0058] In a groove 5 formed in the inner peripheral surface of the outer ring 1, a spring 6 made of a steel plate as a resilient member is engaged. A roller 4 a abutting its tongue 6 a of the spring 6 is biased by the spring in such a direction as to engage the cam surface 2. The biasing force of the tongue 6 a is transmitted to all the rollers 4 through the rollers abutting each other, so that each roller 4 engages the respective cam surface 2 in one direction. Each cam surface 2 is defined by one flat surface.

[0059] On the outer surface of the outer ring 1, a plurality of ribs 7 as torque transmitting means are integrally formed. The one-way clutch is prevented from coming off the rotary shaft 3 by a snap ring 9 through a side plate 8. In this embodiment, when the rotary shaft 3 rotates clockwise, all the rollers 4 are engaged by the cam surfaces 2, so that torque of the rotary shaft 3 is transmitted to the outer ring 1, and the torque transmitted to the outer ring is transmitted to a member engaging the ribs 7. When the rotary shaft 3 rotates counterclockwise, engagement between each roller 4 and the cam surface 2 is released, so that torque is not transmitted and the clutch is in an idling state.

[0060] As shown in FIGS. 2A and 2B, the spring 6 is formed by bending a steel plate. One end of the tongue 6 a is cut into a tapered portion 6 b. After the rollers 4 have been mounted between the outer ring 1 and the rotary shaft 3, the spring 6 is inserted into the space between the outer ring 1 and the rollers 4 from the end face of the outer ring with the tapered end side first, and engaged in the groove 5. By inserting the tapered portion 6 b into the space along the outer peripheral surface of the roller 4 a, the tongue 6 a deflects spontaneously. Thus it is possible to mount the spring 6 smoothly without retaining it by forcibly deflecting the tongue 6 a.

[0061]FIGS. 3 and 4 show the second embodiment. As shown in FIG. 3, with this one-way clutch, too, the outer ring 1 as the outer member is made of a sintered metal. But it differs from the first embodiment in that the resilient member for biasing the rollers 4 into engagement with the cam surfaces 2 is a rubber member 10. Since any other portions are the same as in the first embodiment, they were indicated by the same numerals as in FIG. 1.

[0062] As shown in FIGS. 4A and 4B, the rubber member 10 is an elongated square pole with corners rounded. A tapered portion 10 a is formed at one end thereof. A chamfer 11 is provided at one corner. A corner 12 a adjacent thereto abuts the roller 4 a. The other two corner portions 12 b are fitted in the groove 5. The chamfer 11 is provided to prevent the rubber member 10 from coming into contact with the roller 4 on the opposite side of the roller 4 a when the corner portion 12 a is resiliently deformed upon abutment with the roller 4 a.

[0063] After the rollers 4 have been mounted between the outer ring 1 and the rotary shaft 3, the rubber member 10 is inserted into the space between the outer ring 1 and the rollers 4 from the end face side of the outer ring 1 with the tapered end side first, and engaged in the groove 5. When the tapered portion 10 a is inserted, it is spontaneously elastically deformed so as to fit snugly in the space. Thus it is possible to mount the rubber member 10 smoothly without forcibly deflecting it.

[0064]FIGS. 5 and 6 show the third embodiment. As shown in FIG. 5, with this one-way clutch, the outer ring 1 as the outer member is made of a sintered metal. But it differs from the above embodiments in that the resilient member engaged in its groove 5 is a coil spring 13. Since any other portions are the same as in the first and second embodiments, they were indicated by the same numerals as in FIGS. 1 and 3.

[0065] As shown in FIGS. 6A and 6B, the coil spring 13, too, has one end thereof tapered, and is inserted smoothly in the space between the outer ring 1 and the rollers 4 from the end face side of the outer ring with its tapered end side at first, and engaged in the groove 5.

[0066] FIGS. 7-9 show the fourth embodiment. With this one-way clutch, as shown in FIGS. 7A and 7B, an outer ring 14 as the outer member and an inner ring 15 as the inner member are formed by fine-blanking a steel plate. A plurality of inclined cam surfaces 16 are formed on the outer peripheral surface of the inner ring 15. Between these cam surfaces 16 and an inner cylindrical surface 17 of the outer ring 14, rollers 18 are housed so as to abut one another in a full-type state.

[0067] Side plates 19 for guiding the end faces of the rollers 18 are mounted to both ends of the outer ring 14. The side plates 19 are formed into ring shapes so as to cover the space in which the rollers 18 are housed (FIG. 7A). Four protrusions 20 are provided on one side thereof near the outer periphery at angular spacings of 90°. Each side plate 19 is detachably mounted to the outer ring 14 by fitting these protrusions 20 in an annular groove 21 formed in either end face of the outer ring 14.

[0068] In the outer peripheral surface of the inner ring 15, grooves 22 are formed at two positions. A spring 23 made of a steel plate as a resilient member is engaged in each groove 22. Rollers 18 a that are in abutment with tongues 23 a of springs 23 are biased in such a direction as to engage the cam surfaces 16. Opposite to each spring 23, a small-diameter auxiliary roller 24 is biased toward the outer ring 14 and is disposed between the rollers 18 a and 18 b (FIG. 7B). Thus, at the portions where the auxiliary rollers 24 are disposed, biasing force of the springs 23 toward the side where the rollers 18 engage the cam surfaces 16 is transmitted through the auxiliary rollers 24. At other portions, as in the first to third embodiments, biasing force is transmitted to all the rollers 18 through the rollers, which are in abutment with each other.

[0069] On the outer peripheral surface of the outer ring 14, a plurality of ribs 25 as torque-transmitting means are integrally formed. The end of a rotary shaft is adapted to be fitted in a square hole 26 formed in the inner periphery of the inner ring 15 and having corners rounded. In this embodiment, when the inner ring 15 rotates clockwise or the outer ring 14 rotates counterclockwise, all the rollers 18 engage the cam surfaces 16. When the inner ring 15 or outer ring 14 rotate in the opposite direction, engagement is released. Each cam surface 16 is formed by a combination of two flat surfaces.

[0070] As shown in FIGS. 9A and 9B, each spring 23 is formed by cutting and bending a steel plate. The tongue 23 a has its one end bent inwardly in a triangular shape and tapered by the formation of a bent portion 23 b. After the rollers 18 have been mounted between the outer ring 14 and the inner ring 15, the springs 23 are inserted in the spaces between the inner ring 15 and the rollers 18 a, 18 b and 24 with the side formed with the bent portion 23 b at first, and engaged in the respective grooves 22. By inserting the bent portion 23 b along the outer peripheral surface of the roller 18 a, the tongue 23 a deflects spontaneously, so that it is possible to mount the springs 23 smoothly without forcibly deflecting the tongue 23 a.

[0071]FIGS. 10 and 11 show the fifth embodiment. With this one-way clutch, the basic structure is the same as the fourth embodiment, but it differs therefrom in that instead of the annular grooves 21 formed at both end faces of the outer ring 14 for engaging the protrusions 20 on the side plates 19, four holes 27 are formed at angular intervals of 90° and that as shown in FIGS. 11A and 11B, alternate rollers 18 housed in a full type state are replaced with grooved rollers 28 having the same outer diameter and having an annular groove 28 a. Since any other portions are the same as in the fourth embodiment, they were indicated by the same numerals as in FIG. 7.

[0072] The grooved rollers 28 are used to improve the retaining ability of grease or oil on the cam surfaces 16 and the cylindrical surface 17 defining the space housing the rollers. These grooved rollers 28 do not necessarily have to be arranged alternately but by replacing one or more rollers 18 with grooved rollers 28, it is possible to improve the retaining ability of grease and oil and reduce the idling torque of the one-way clutch.

[0073]FIGS. 12A and 12B show further embodiments modified in replacement of rollers 18 shown in FIG. 11. FIG. 12A is an embodiment in which alternating rollers 18 are replaced with short rollers 29 having the same outer diameter but shorter in length. FIG. 12B shows an embodiment in which one roller 18 is replaced with two balls 30 having the same outer diameter as the rollers 18.

[0074] In the fourth and fifth embodiments, the side plates on both sides for guiding end faces of the rollers are in engagement with the outer ring as the outer member. But they may be engaged with the inner ring as the inner member. Only one of the side plates may be engaged.

[0075]FIGS. 13A and 13B show the sixth embodiment. This one-way clutch 31 is for a stator of a torque converter used in an automotive automatic transmission, and the inner ring 32 and the outer ring 33 are both made of a sintered metal. The basic structure of the clutch portion is the same as in the fourth and fifth embodiments. On the outer peripheral surface of the inner ring 32, a plurality of cam surfaces 34 and two grooves 35 are formed. Between the outer surface of the inner ring 32 and the inner surface of the outer ring 33, the rollers 37 disposed in a full type state through two auxiliary rollers 36 are biased in such a direction as to engage each cam surface 34 by a steel spring 38 engaged in each groove 35.

[0076] The inner ring 32 has a wide stepped portion on its inner periphery side, on which serrations 39 as torque-transmitting means are formed. As shown in the FIG. 14, by coupling through the serrations 39, it is fixed to a stator shaft 48.

[0077] The outer ring 33 is also formed with a plurality of ribs 40 as torque-transmitting means on its outer periphery. Through these ribs 40, it is coupled to the inner periphery of the stator 49 as a rotary member. With this one-way clutch 31, when the outer ring 33 rotates counterclockwise with its inner ring 32 fixed, all the rollers 37 are engaged by the cam surfaces 34. During rotation in the opposite direction, engagement is released, so that the outer ring 33 idles together with the stator 49.

[0078] In the surface of each roller 37, a multiplicity of independent, minute recesses are formed in a random manner. Its surface roughness is such that the ratio RMS (L)/RMS (C) of the axial average surface roughness RMS (L) of the rollers 37 to the circumferential average surface roughness RMS (C) is 1.0 or under and the SK value, which is a parameter of surface roughness, is −1.6 or under both in the axial and circumferential directions.

[0079] Thus, since a sufficient oil film is formed for the circumferential sliding of the rollers 37, wear of the rollers due to sliding during idling is effectively suppressed and also the idling torque decreases. Also, an annular groove 41 is formed in the inner cylindrical surface of the outer ring 33 to increase the lubricating oil retaining ability and thus to reduce the idling torque.

[0080]FIG. 14 shows the one-way clutch 31 mounted in a torque converter 42 of an automatic transmission. This torque converter 42 basically comprises a pump impeller 44 coupled to an output shaft 43 of an engine, a turbine runner 46 arranged opposite the pump impeller 44 and coupled to an input shaft 45 of the transmission, and a stator 49 arranged between the pump impeller 44 and a turbine runner 46 and mounted through the one-way clutch 1 on a stator shaft 48 fixed to a casing 47.

[0081] When fluid circulating between the bowl-shaped pump impeller 44 and turbine runner 46 is returned from the turbine runner 46 to the pump impeller 44 on their inner-diameter side, the stator 49 serves to apply a turning force in a normal direction to the pump impeller 44 by changing the flow direction of the fluid to amplify the transmitted torque.

[0082] As described above, the inner ring 32 of the one-way clutch 31 is fixed to the stator shaft 48 through the serrations 39, while its outer ring 33 is coupled to the inner periphery of the stator 49 through the ribs 40. When the stator 49 receives a reaction force for changing the flow direction of the fluid, each roller 37 engages the respective cam surface 34 to bear the reaction force.

[0083]FIGS. 15A and 15B show the seventh embodiment. This one-way clutch has a plurality of cam surfaces 51 and a groove 52 formed on the outer peripheral surface of the inner ring 50. The rollers 54 arranged between the outer surface of the inner ring 50 and the inner surface of the outer ring 53 in a full type state are biased by a steel spring 55 in such a direction as to engage the respective cam surface 51. The inner ring 50 and the outer ring 53 are formed by blanking a steel plate.

[0084] The inner periphery of the inner ring 50 is shaped into a square hole 56 having rounded corners as a torque-transmitting means. The outer peripheral surface of the outer ring 53 is provided with chamfers 57 at 90° intervals at four points as torque-transmitting means. With this one-way clutch, when the inner ring 50 turns clockwise or the outer ring 53 turns counterclockwise, all the rollers 54 engage the cam surfaces 51, and when they rotate in the opposite direction, engagement is released.

[0085] As with the sixth embodiment, in the surface of each roller 54, a multiplicity of independent, minute recesses are randomly formed. Its surface roughness is such that the ratio RMS (L)/RMS (C) of the axial average surface roughness RMS (L) of the rollers 54 to the circumferential average surface roughness RMS (C) is 1.0 or under and the SK value, which is a parameter of surface roughness, is −1.6 or under both in the axial and circumferential directions of the rollers 54. Further, an annular groove 58 is formed in the inner peripheral surface of the outer ring 53 to achieve excellent wear suppressing effect for the rollers and good idling properties.

[0086] While in each of the above embodiments, each cam surface was formed by one flat surface or a combination of two flat surfaces, it may be formed of a curved surface. Also, strictly speaking, a slight clearance is permitted between the rollers in a full type state in each embodiment. The permissible amount of clearance is set bellow the amount of resilient displacement of the rollers and inner and outer rings during rated loading of the one-way clutch so that all the rollers can be kept abutting one another during rated loading.

[0087] As described above, with the one-way clutch of this invention, since the rollers adapted to engage the inclined cam surfaces formed on the inner peripheral surface of the outer member or the outer peripheral surface of the inner member are provided in a full type state, and engage the inner peripheral surface of the outer member or the outer peripheral surface of the inner member without disposing any roller-biasing resilient members between the rollers, so that all the rollers can maintain a mutually abutting state directly or through the auxiliary rollers, it is possible to reliably and instantly transmit the biasing force of the resilient member to all the rollers. Thus, a reduction in the torque-transmitting ability will not happen, and also the responsiveness of turning on and off of the clutch is improved. 

What is claimed is:
 1. A one-way clutch comprising an outer member having an inner peripheral surface, an inner member having an outer peripheral surface, one of said inner and outer peripheral surfaces being formed with a plurality of inclined cam surfaces and the other being formed into a cylindrical surface, rollers as engaging members arranged between said outer member and said inner member at such positions as to oppose said cam surfaces, and a resilient member for biasing said rollers in such a direction as to engage said cam surfaces, characterized in that said rollers are brought into abutment with one another directly or through auxiliary rollers having a smaller diameter than said rollers, and that said resilient member is brought into engagement with one of the inner peripheral surface of said outer member and the outer peripheral surface of said inner member to transmit the biasing force of said resilient member to all of said rollers through said rollers abutting one another.
 2. The one-way clutch as claimed in claim 1 wherein at least one of said outer member and said inner member is made of a sintered metal.
 3. The one-way clutch as claimed in claim 1 wherein at least one of said outer member and said inner member is formed by blanking a steel plate.
 4. The one-way clutch as claimed in claim 3 wherein said blanking is fine-blanking to the finished dimension of said outer member or inner member.
 5. The one-way clutch as claimed in any of claims 1-4 wherein said auxiliary rollers are arranged at positions where said resilient members are provided.
 6. The one-way clutch as claimed in any of claims 1-5 wherein said resilient member is a steel spring having a tongue biasing said roller.
 7. The one-way clutch as claimed in any of claims 1-6 wherein a torque-transmitting means is formed on the outer periphery of said outer member.
 8. The one-way clutch as claimed in claim 7 wherein said torque-transmitting means is ribs formed on the outer periphery of said outer member.
 9. The one-way clutch as claimed in any of claims 1-8 wherein at least one of said rollers is replaced by an engaging element having the same outer diameter as said rollers and having a different shape therefrom.
 10. The one-way clutch as claimed in claim 9 wherein said engaging element having a different shape is a grooved roller formed with at least one annular groove on its cylindrical surface.
 11. The one-way clutch as claimed in claim 9 wherein said engaging element having a different shape is a short roller shorter in length than said rollers.
 12. The one-way clutch as claimed in any of claims 1-11 wherein a multiplicity of independent, minute recesses are formed in the surface of said rollers in a random manner.
 13. The one-way clutch as claimed in claim 12 wherein the surface of said rollers formed with said recesses has such an average surface roughness that when indicated in terms of minimum root mean square RMS, the ratio RMS (L)/RMS (C) of the axial average surface roughness RMS (L) of the rollers to the circumferential average surface roughness RMS (C) is not more than 1.0 and the SK value, which is a parameter of surface roughness, is not more than −1.6 both in the axial and circumferential directions of said rollers.
 14. The one-way clutch as claimed in any of claims 1-13 wherein in the inner peripheral surface of said outer member or the outer peripheral surface of said inner member that is formed with said cam surfaces, at least one groove extending in an axial direction is formed, and said resilient member is engaged in said groove.
 15. The one-way clutch as claimed in claims 14 wherein said resilient member engaged in said groove has one end thereof tapered.
 16. The one-way clutch as claimed in any of claims 1-15 wherein side plates are provided for guiding both end faces of said rollers, at least one of said side plates having means for engaging an end face of said outer member or inner member.
 17. The one-way clutch as claimed in claim 16 wherein said means for engaging is protrusions provided on said side plate at a plurality of points so as to engage in recesses formed in the end face of said outer member or inner member.
 18. The one-way clutch as claimed in any of claims 1-17 wherein said cam surfaces are formed on the outer periphery of said inner member, wherein said resilient member is brought into engagement with the outer periphery of said inner member, and wherein a torque-transmitting means is formed on the inner periphery of said inner member.
 19. The one-way clutch as claimed in claim 18 wherein said torque-transmitting means is a serration.
 20. The one-way clutch as claimed in claim 18 or 19 wherein an annular groove is formed in an inner peripheral surface of said outer member. 